Adjustable flat wrenches, such as Crescent wrenches, are well known and comprise a pair of jaws which are opened and closed in response to rotation of an adjustment screw rotatably disposed in the wrench body and usually operable by a user's thumb. A given direction of rotation of the adjustment screw will cause opening of the wrench jaws when the wrench is in one operating position, and will cause closure of the wrench jaws when the wrench is in the opposite operating position. Although the movement of the jaws in response to a given adjustment screw rotation can be remembered or learned for each wrench position, usually a user will rotate the adjustment screw in one direction and reverse the direction of the jaws are not moving in the intended manner.